Explanation of Co-Witness

[sspro2340]

For a new person to RDS this discussion has been valuble. My head is spinning a little but I will go back and re-read some of the parts to understand even more. I just bought an Aimpoint with LaRue LT150 mount and it looks like the iron sights (FFSB and MI fixed rear sight) are visible in the lower 1/3 of the tube when the RDS is on. I have NOT sighted anything in yet (my range is closed Jan and Feb) so I have some time to do some more reading and research.
Thank you for all of the opinions and info.
P.S. Does eye relief for the RDS have any bearing on the 1/3 or absolute co witness discussion??? What is a good place to put the RDS to start???
Thank you.

by "put" for the rds are you referring to the actual unit, or do the dot itself? I am assuming you mean the rds...from my understanding and from the instruction i received you want to put the rds about in the middle of the gun say just before your delta ring/notch on your flattop
from what i remember this is done for control issues (keeping the weight of the optic centered on the system) and for "Tracking"

tracking the red dot: as you are looking at your target and bringing the optic to your eye to engage your peripheral vision will instantly see the red dot and you will be able to track it onto your target

its been awhile so if this isn't 100% sry, but no one else has answered u in a month or so, so i thought id give it a shot

[tgace]

I always zero my irons then dial my dot to the front sight post tip to "put it in the neighborhood". Then I zero my dot.

[sspro2340]

I thought I would throw up some pictures (since I'm more of a visual learner and this took me a while to get through my thick skull) to give folks a better idea on what the irons and rds looks like together and in terms of different sized mounts.

None of these pics are mine, I do not take credit for their work but appreciate every one of them, some are from users on calguns.net, another one of the pics is from ar15.com, and of course larue, or maybe another user from here, can't remember I apologize if one of these are yours and I did not mention you.

Here's a vid as well VID HERE

PICS




My question is how does all this look when you have a foldable rear sight and a fixed front sight?

[Singlestack Wonder]

I thought I would throw up some pictures (since I'm more of a visual learner and this took me a while to get through my thick skull) to give folks a better idea on what the irons and rds looks like together and in terms of different sized mounts.

None of these pics are mine, I do not take credit for their work but appreciate every one of them, some are from users on calguns.net, another one of the pics is from ar15.com, and of course larue, or maybe another user from here, can't remember I apologize if one of these are yours and I did not mention you.

Here's a vid as well VID HERE

PICS




My question is how does all this look when you have a foldable rear sight and a fixed front sight?

The same if the rear folding sight is up.

[Blkgunuser]

I thought I would throw up some pictures (since I'm more of a visual learner and this took me a while to get through my thick skull) to give folks a better idea on what the irons and rds looks like together and in terms of different sized mounts.

None of these pics are mine, I do not take credit for their work but appreciate every one of them, some are from users on calguns.net, another one of the pics is from ar15.com, and of course larue, or maybe another user from here, can't remember I apologize if one of these are yours and I did not mention you.

Here's a vid as well VID HERE

PICS




My question is how does all this look when you have a foldable rear sight and a fixed front sight?

Thanks for this AWSOME pictorial of an explanation. https://www.m4carbine.net/images/smi...ew/dance3.gifI know it's LaRue's stuff, but I was not aware of it myself. There should be no reason anybody should not get this topic by now. This is my first post here. I've been a lurker (registered member and not) for a couple of years now. And this 1/3 witness/co-witness has been going on toooo long already. Please sticky this picture up for those who cannot visually obtain the concept through verbal description. https://www.m4carbine.net/images/smi...ew/suicide.gif

This site has provided me with an enormous amount of information and has assisted me in my weapon(s) and accessories selection. I want to thank everybody again for a great site/tool to refer to for REAL help.

[sspro2340]

Thanks for this AWSOME pictorial of an explanation.

No problem man, glad it helped

I remember it took me awhile to grasp the concept.

The above items posted were the sort of poignant moments that totally turned on the light bulb and lit up the entire valley for me

[Doc Safari]

For the life of me I cannot get the different elements to line up this way. I tried it with both eyes open and I think with one eye closed if I'm not mistaken.

I am using an Aimpoint T-1 w/LRP Mount & Spacer. I have tried getting the sight pictures in that pic with a Daniel Defense DD 1.5, a LaRue quick detachable fixed rear sight (the number escapes me right now), and the LMT M16A2 style rear sight (the one that looks like the chopped carry handle).

I have not been to the range to zero anything yet. I've just been experimenting with whether or not to go with folding or fixed rear sight and so I've been trying out different rear sights and the resulting sight pictures.

It seems that if the dot is centered in the Aimpoint then the dot is above the front sight post (fine since the rear BUIS is not being used), and the loop of the rear sight is canted. Then when I lower my head to look through the rear aperture, nothing remains lined up and I have to re-orient everything to get the dot centered, etc.

What am I doing wrong?

Will this tend to correct itself when I get the irons and the Aimpoint zeroed?

I wear pretty thick glasses, so I appreciate being able to hold my head high to see the dot in the Aimpoint. I also appreciate being able to "index" the dot to the front sight post although I understand some people say you shouldn't or shouldn't have to do this. But it's not going to do my any good to zero all the elements together unless I can get a good sight picture with the dot centered in the irons.

I was told years ago by an eye doctor that my eyes do not work together so I'm wondering if that's my answer right there.

Right now I'm ready to concede that the irons on my carbine will only be used if the red dot goes down, but I was really wanting to try out a cowitness.

Anybody? Am I doing something wrong?

[ArmaGlock]

For the life of me I cannot get the different elements to line up this way. I tried it with both eyes open and I think with one eye closed if I'm not mistaken.

I am using an Aimpoint T-1 w/LRP Mount & Spacer. I have tried getting the sight pictures in that pic with a Daniel Defense DD 1.5, a LaRue quick detachable fixed rear sight (the number escapes me right now), and the LMT M16A2 style rear sight (the one that looks like the chopped carry handle).

I have not been to the range to zero anything yet. I've just been experimenting with whether or not to go with folding or fixed rear sight and so I've been trying out different rear sights and the resulting sight pictures.

It seems that if the dot is centered in the Aimpoint then the dot is above the front sight post (fine since the rear BUIS is not being used), and the loop of the rear sight is canted. Then when I lower my head to look through the rear aperture, nothing remains lined up and I have to re-orient everything to get the dot centered, etc.

What am I doing wrong?

Will this tend to correct itself when I get the irons and the Aimpoint zeroed?

I wear pretty thick glasses, so I appreciate being able to hold my head high to see the dot in the Aimpoint. I also appreciate being able to "index" the dot to the front sight post although I understand some people say you shouldn't or shouldn't have to do this. But it's not going to do my any good to zero all the elements together unless I can get a good sight picture with the dot centered in the irons.

I was told years ago by an eye doctor that my eyes do not work together so I'm wondering if that's my answer right there.

Right now I'm ready to concede that the irons on my carbine will only be used if the red dot goes down, but I was really wanting to try out a cowitness.

Anybody? Am I doing something wrong?

The first thing I'm going to tell you that might clarify things is that the Aimpoint is parallax free, simply stated, you don't have to center the dot inside of the optic. Just put the dot where you want to shoot.

You have the LRP with spacer which puts the iron sights in the bottom 1/3 of the optic glass, so when not looking through your rear sight the dot SHOULD be above the front sight post.

When you look through your rear sight, if your irons and optic have been zeroed to the same distance the dot should sit on the tip of the front sight and be centered (or close to it). I say close to it, because my dot has always sat on the tip, but just a little to the left of my front sight. That's on two separate rifles with different type iron sights. I have always zeroed my irons, brought the dot as close as possible and then zeroed the optic independently.

Hope this helps.

[Doc Safari]

The first thing I'm going to tell you that might clarify things is that the Aimpoint is parallax free, simply stated, you don't have to center the dot inside of the optic. Just put the dot where you want to shoot.

You have the LRP with spacer which puts the iron sights in the bottom 1/3 of the optic glass, so when not looking through your rear sight the dot SHOULD be above the front sight post.

When you look through your rear sight, if your irons and optic have been zeroed to the same distance the dot should sit on the tip of the front sight and be centered (or close to it). I say close to it, because my dot has always sat on the tip, but just a little to the left of my front sight. That's on two separate rifles with different type iron sights. I have always zeroed my irons, brought the dot as close as possible and then zeroed the optic independently.

Hope this helps.

It does, thanks.

I think this gets back to what I've complained about as "visual clutter." A person (me) focuses so much on the different sight elements lining up or not that they forget to consider the target. I know some trainers and some shooters have learned to insist on cowitness, but I think I may have to join the ranks of those who use a folding rear sight exclusively so that I'm more comfortable with the uncluttered sight picture. Too bad I wasted money on a couple of fixed rear BUIS's before buying the RDS.

[ArmaGlock]

I think the flip-up vs. fixed is simply personal preference. Fixed sights work for some, but not for others when running an optic. I run fixed Troy sights and ran a Larue rear and standard FSB on my old rifle with an Aimpoint Comp C3. I just switched to an H-1 with Larue mount (1/3 also) and so far it's working well with fixed also. It didn't happen overnight, I've just learned to ignore the fixed over the 4 or 5 years I have been running them with the optic.

A good friend of mine runs flip-up Troys with his T-1 and is bothered by the "clutter" of fixed sights.

I think as long as you have a quality rear flip-up sight you are good to go. None of the instructors I have been to (Paul Howe, Frank Garcia, and local guys on my department with real world gun fight experience) have made a big issue about flip up sights, as long as you have some sort of quality BUIS. Not having them is frowned upon and a fail in my opinion if you use your rifle for self-defense or any other real world scenario.

Try selling the fixed sights you have and go with a flip-up rear sight.

I suggest zeroing them separately at the same distance and only worrying about them lining up when you look through the sights as a point of reference. Then do most of your shooting with your optic and occasionaly turn off the optic and shoot with your irons through the optic in order to stay proficient.

Just my .02.